Re: [Watchdog drivers] - WDIOC_GETSUPPORT clarification

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 8/18/21 11:57 AM, Jose Noguera wrote:
> Hello all!
> 
> I’m Jose, working in Red Hat on Fedora IoT and RHEL For Edge related projects.
> 
> While trying to add the feature of figuring out whether the current boot was triggered or not by a hardware watchdog using wdctl, we’ve found an odd behaviour in the drivers definition that we would like to check with you.
> 
> Looking specifically for the flag WDIOF_CARDRESET, we can find 40 files that contain it:
> 
> $ grep -rl CARDRESET drivers/watchdog/ | wc -l
> 40
> 
> but only 19 of them have the flag advertised in the options field of the watchdog_info struct returned by the WDIOC_GETSUPPORT ioctl.
> 
> This leads to wdctl not showing WDIOF_CARDRESET for drivers like i6300esb, even when the board had been reset this way:
> 
> $ sudo wdctl
> Device: /dev/watchdog0
> Identity: i6300ESB timer [version 0]
> Timeout: 30 seconds
> Pre-timeout: 0 seconds
> 
> FLAG DESCRIPTION STATUS BOOT-STATUS
> KEEPALIVEPING Keep alive ping reply 1 0
> MAGICCLOSE Supports magic close char 0 0
> SETTIMEOUT Set timeout (in seconds) 0 0
> 
> Working with Hans (in CC), we added a little patch (BugZilla ticket: 1993983) on wdctl

To be clear, Jose is talking about this bugzilla:
https://bugzilla.redhat.com/show_bug.cgi?id=1993983

And this is the util-linux commit with the little workaround-patch:
https://github.com/karelzak/util-linux/commit/b1b0259fe42aad1bf0997ce1c03a020ce59e38ab

> and this would be the output of the command when it was a card reset triggered boot:
> 
> $ sudo wdctl
> Device: /dev/watchdog0
> Identity: i6300ESB timer [version 0]
> Timeout: 30 seconds
> Pre-timeout: 0 seconds
> 
> FLAG DESCRIPTION STATUS BOOT-STATUS
> CARDRESET Card previously reset the CPU 1 1
> KEEPALIVEPING Keep alive ping reply 1 0
> MAGICCLOSE Supports magic close char 0 0
> SETTIMEOUT Set timeout (in seconds) 0 0
> 
> So our question is, may we know what is intended to be present in ident.options? What should the API call WDIOC_GETSUPPORT return in the options field?

Regards,

Hans